オクチルフェニルリン酸による硫酸溶液からのガリウム (III), インジウム (III) およびアルミニウム (III) の抽出・分離

Abstract

Extractions of gallium(III), indium(III) and aluminium(III) from sulfuric acid solutions by octylphenyl phosphoric acid (OPAP) diluted in benzene were investigated under various aqueous conditions. Infrared spectra and high resolution nuclear magnetic resonance spectra were also studied for extracted organic phase in order to elucidate the extraction mechanism.Extraction of these metals decrease with an increase in aqueous acid concentrations. The order of extraction efficiency by OPAP is In(III)>Ga(III)>A1(III). Separation factors for indium/gallium, indium/aluminium and gallium/aluminium systems are calculated to 6x102, 1x104 and 30 respectively at 0.1 mol dm-3 sulfuric acid concentration in case of 2.5% OPAP, It is apparent from the separation factors that the separation of indium from gallium, indium from aluminium and gallium from aluminium are feasible.From IR spectra, it is proved that the extraction mechanism by OPAP is similar to that by di-2-ethylhexyl phosphoric acid (DEHPA). It is suggested from NMR spectra that the introduction of phenyl groups is effective for extractions of gallium and indium from sulfuric acid solutions.The recovery of gallium and indium from sulfuric acid solutions by OPAP has been carried out for mixed solutions containing gallium, indium and aluminium with results of a good agreement between the expected and experimental data.